fix: allow for null value in deserialized node

[alanshaw]

typeof null is 'object'

Fixes:

TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at /Users/alan/Code/pl/ipfs/js-ipfs/node_modules/dag-cbor-links/index.js:10:28
    at Generator.next (<anonymous>)
    at /Users/alan/Code/pl/ipfs/js-ipfs/node_modules/dag-cbor-links/index.js:30:21
    at Generator.next (<anonymous>)
    at /Users/alan/Code/pl/ipfs/js-ipfs/src/core/components/pin/pin-manager.js:62:34
    at async run (/Users/alan/Code/pl/ipfs/js-ipfs/node_modules/p-queue/dist/index.js:255:29)

Depends on:

• chore: update dependencies dag-cbor-sync#34

[mikeal]

Published 1.3.2